In general, in cases where a plurality of elevators are generally installed in a building, an elevator group control system is applied in order to manage a plurality of elevators in an efficient manner and to shorten passenger's waiting time.
In addition, such a kind of elevator group control system is intended to shorten transportation completion times required to transport passengers to their destination floors, as well as to shorten service completion times, while permitting some extension of passenger's waiting times.
A conventional elevator group control system is provided, as an optimal assignment device for car calls, with a call registration unit to register a passenger's destination floor call together with a hall call, and a maximum number determination unit to determine a maximum number of car calls to be assigned to each car, these units being arranged in each elevator hall, wherein in cases where the maximum number of car calls for a car is exceeded, the exceeded car calls are assigned to another car or cars, so that the number of stopping floors up to each passenger's destination floor is decreased to achieve the shortening of the service completion time (for example, see a first patent document).
FIG. 5 is an explanatory view showing an assignment operation according to the conventional system described in the first patent document, wherein a case is illustrated in which cars 3A-3C of a plurality of elevators #A-#C are installed in a building having floors 1F-10F as service floors.
In FIG. 5, for example, let us assume that in cases where a hall call 5A has been generated on the floor 4F and destination floor calls 6A, 6B to the floors 5F, 6F have been generated, this call has been assigned to the car 3A based on priorities such as arrival prediction time evaluation values.
In addition, let us assume that thereafter, in the car 3B, car calls 7A, 7B to the floors 4F, 10F have been registered, and a hall destination call 8 to the floor 10F has newly been generated on the floor 4F.
In this case, there occurs a phenomenon in which although it is already decided that the car 3B is scheduled to stop at the floors 4F and 10F, the new hall destination call 8 has not been assigned to the car 3B but to the car 3A.
That is, if a “maximum number” for the number of stops permitted to the car 3A is “4”, new calls will be assigned to the car 3A until the number of stops of the car 3A amounts to “4”, as a result of which when the destination floor call of the hall call 8 newly generated on the floor 4F is for “the floor 10F”, it is assigned to the car 3A.
[First Patent Document] Japanese patent application laid-open No. S63-218484